From a wide moulded base (of a vase?) retaining yellow color. Base of P 18692.
Cf. P 8018 (ΚΚ 811), but not from it. Cistern system 3, east chamber, strosis 4, hard water deposit. Leica PD 1231-10 ... 11 June 1936 ... Burr Thompson (1973), no. 189, p. 182, pl. LVI.